Continuous acoustic chemical microreactor

ABSTRACT

A continuous acoustic chemical microreactor system is disclosed. The system includes a continuous process vessel (CPV) and an acoustic agitator coupled to the CPV and configured to agitate the CPV along an oscillation axis. The CPV includes a reactant inlet configured to receive one or more reactants into the CPV, an elongated tube coupled at a first end to the reactant inlet and configured to receive the reactants from the reactant inlet, and a product outlet coupled to a second end of the elongated tube and configured to discharge a product of a chemical reaction among the reactants from the CPV. The acoustic agitator is configured to agitate the CPV along the oscillation axis such that the inner surface of the elongated tube accelerates the one or more reactants in alternating upward and downward directions along the oscillation axis.

RELATED APPLICATIONS

This patent application is a continuation-in-part of U.S. patentapplication Ser. No. 13/965,964, filed on Aug. 13, 2013, entitled“Mechanical System That Continuously Processes A Combination OfMaterials,” which claims the benefit of U.S. Provisional PatentApplication No. 61/742,923, filed on Aug. 20, 2012, entitled “ContinuousAcoustic Processing,” and is a continuation-in-part of InternationalApplication No. PCT/US2013/043755, filed on May 31, 2013, entitled“Mechanical System That Fluidizes, Mixes, Coats, Dries, Combines,Chemically Reacts, and Segregates Materials,” which itself claims thebenefit of U.S. Provisional Patent Application No. 61/689,256, filed onMay 31, 2012, entitled “Mechanical System That Fluidizes, Mixes, Coats,Dries, Combines, Chemically Reacts, or Segregates Materials.” Thedisclosure of each of the aforementioned applications is incorporatedherein by reference.

BACKGROUND

A continuous acoustic mixer (CAM) is a device that can impart acousticenergy onto one or more materials passing through it. The acousticenergy can mix, react, coat, or combine the materials. The CAM can oftenprocess materials more quickly and uniformly than batch mixers.

SUMMARY

At least one aspect is directed to a continuous acoustic chemicalmicroreactor system. The system includes a continuous process vesselconfigured to oscillate along an oscillation axis. The continuousprocess vessel includes a reactant inlet configured to receive one ormore reactants into the continuous process vessel. The continuousprocess vessel includes an elongated tube coupled at a first end to thereactant inlet and configured to receive the reactants from the reactantinlet. The elongated tube has an inner surface having a hydraulicdiameter of less than 2.5 cm. The continuous process vessel includes aproduct outlet coupled to a second end of the elongated tube andconfigured to discharge a product of a chemical reaction among thereactants from the continuous process vessel. The system includes anacoustic agitator coupled to the continuous process vessel andconfigured to agitate the continuous process vessel along theoscillation axis such that the inner surface of the elongated tubeaccelerates the one or more reactants in alternating upward and downwarddirections along the oscillation axis.

In some implementations, the acoustic agitator can be configured toagitate the continuous process vessel with an acceleration greater than60 g.

In some implementations, the elongated tube can be at least 10 cm long.

In some implementations, the elongated tube can have an inner surfacehaving a hydraulic diameter of less than 0.5 cm.

In some implementations, the continuous process vessel can include acoolant inlet configured to receive a cooling fluid, an interstitialregion within the continuous process vessel and surrounding theelongated tube, and a coolant outlet for discharging the cooling fluidfrom the interstitial region. The interstitial region can be configuredto receive the cooling fluid and bring it into contact with an outersurface of the elongated tube.

In some implementations, the continuous process vessel can include aheater inlet configured to receive a heating fluid, an interstitialregion within the continuous process vessel and surrounding theelongated tube, and a heater outlet for discharging the heating fluidfrom the interstitial region. The interstitial region can be configuredto receive the heating fluid and bring it into contact with an outersurface of the elongated tube.

In some implementations, the inlet can be configured to receive atransport gas.

In some implementations, the system can be configured to operate atmechanical resonance.

In some implementations, the system can include a second reactant inletcoupled to the elongated tube at a point between the first end and thesecond end and configured to receive a midstream reactant and introduceit into the elongated tube.

In some implementations, the inner surface of the elongated tube canhave a cross section that is substantially circular.

In some implementations, the inner surface of the elongated tube canhave a cross section that is substantially ovular.

In some implementations, the inner surface of the elongated tube canhave a cross section that is substantially rectangular.

In some implementations, the inner surface of the elongated tube canhave a cross section that is substantially square.

In some implementations, the inner surface of the elongated tube canhave a cross section that is substantially triangular.

In some implementations, the inner surface of the elongated tube can besmooth.

In some implementations, the inner surface of the elongated tube can berough.

In some implementations, the inner surface of the elongated tube can becoated with a catalyst.

In some implementations, the acoustic agitator can be configured toagitate the continuous process vessel at a frequency greater than 10 Hzand less than 100 Hz.

At least one aspect is directed to a method of continuously processing acombination of materials in a chemical microreactor. The method includesintroducing, via a reactant inlet, one or more reactants into anelongated tube coupled at a first end to the reactant inlet andconfigured to receive the reactants from the reactant inlet. Theelongated tube has an inner surface having a hydraulic diameter of lessthan 2.5 cm. The method includes agitating, using an acoustic agitatorcoupled to the continuous process vessel, the continuous process vesselalong the oscillation axis such that the inner surface of the elongatedtube accelerates the one or more reactants in alternating upward anddownward directions along the oscillation axis. The method includesdischarging, from a product outlet coupled to a second end of theelongated tube, a product of a chemical reaction among the reactantsfrom the continuous process vessel.

In some implementations, the method can include introducing, via acoolant inlet, a cooling fluid into an interstitial region within thecontinuous process vessel and surrounding the elongated tube, anddischarging, via a coolant outlet, the cooling fluid from theinterstitial region. The interstitial region can be configured toreceive the cooling fluid and bring it into contact with an outersurface of the elongated tube.

In some implementations, the method can include introducing, via aheater inlet, a heating fluid into an interstitial region within thecontinuous process vessel and surrounding the elongated tube, anddischarging, via a heater outlet, the heating fluid from theinterstitial region. The interstitial region can be configured toreceive the heating fluid and bring it into contact with an outersurface of the elongated tube.

In some implementations, the method can include introducing a midstreamreactant into the elongated tube via a second reactant inlet coupled tothe elongated tube at a point between the first end and the second end.

In some implementations, the method can include introducing a transportgas into the reactant inlet. In some implementations, the transport gasis introduced to maintain a gas fraction in the elongated tube greaterthan 5% and less than 90%.

In some implementations, the method can include agitating the continuousprocess vessel with an acceleration greater than 60 g.

In some implementations, the method can include agitating the continuousprocess vessel at a frequency greater than 10 Hz and less than 100 Hz.

In some implementations, the method can include agitating the continuousprocess vessel at a mechanical resonance of the combined acousticagitator and continuous process vessel system.

These and other aspects and implementations are discussed in detailbelow. The foregoing information and the following detailed descriptioninclude illustrative examples of various aspects and implementations,and provide an overview or framework for understanding the nature andcharacter of the claimed aspects and implementations. The drawingsprovide illustration and a further understanding of the various aspectsand implementations, and are incorporated in and constitute a part ofthis specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are not intended to be drawn to scale. Likereference numbers and designations in the various drawings indicate likeelements. For purposes of clarity, not every component may be labeled inevery drawing. In the drawings:

FIG. 1 is a diagram of a continuous acoustic mixer for continuouslyprocessing a combination of materials, according to an illustrativeimplementation;

FIG. 2 shows a cutaway view of a continuous process vessel, according toan illustrative implementation;

FIG. 3 shows an example process vessel suitable for use as a continuousacoustic chemical microreactor, according to an illustrativeimplementation;

FIG. 4 shows an example process vessel having a second inlet forreceiving a midstream reactant, and suitable for use as a continuousacoustic chemical microreactor, according to an illustrativeimplementation;

FIGS. 5A and 5B show example experimental setups of continuous acousticchemical microreactors, according to an illustrative implementation;

FIG. 6A shows example results of experiments conducted with thecontinuous acoustic chemical microreactor shown in FIG. 5B at differentinlet gas flows and accelerations;

FIG. 6B shows example results of experiments conducted with thecontinuous acoustic chemical microreactor shown in FIG. 5B versus aCorning Advanced-Flow™ Reactor at different inlet gas flows andaccelerations;

FIG. 7A shows example results of experiments conducted with a continuousacoustic chemical microreactor measuring mixing time versusacceleration;

FIG. 7B shows example results of experiments conducted with a continuousacoustic chemical microreactor measuring mix quality versusacceleration;

FIG. 8 is a flowchart of an example method of continuously processing acombination of materials in a chemical microreactor, according to anillustrative implementation;

FIGS. 9A and 9B illustrate horizontal cross sections of an examplehorizontal plate process vessel suitable for use as a continuousacoustic chemical microreactor, according to an illustrativeimplementation;

FIG. 9C illustrates a vertical cross sections of an example horizontalplate process vessel suitable for use as a continuous acoustic chemicalmicroreactor, according to an illustrative implementation; and

FIG. 9D illustrates a perspective view of an example horizontal plateprocess vessel suitable for use as a continuous acoustic chemicalmicroreactor, according to an illustrative implementation.

DETAILED DESCRIPTION

A continuous processing system is described herein that has distinctivefeatures that separate it from other mixers currently available, such aslaminar regime mixers. The continuous processing system operates atmechanical resonance that enables large vibrational amplitudes atlow-frequencies, for example, in the range of between about 30 Hz toabout 1 kHz. In some implementations, the system operates at about 60Hz. These large amplitudes create a strong sinusoidal acoustic fieldinside of a mixing reactor or a continuous process vessel, whichprovides efficient and intense mixing and reacting. Additionally, thedisplacement of plates or other structures disposed within thecontinuous process vessel can impose large acceleration forces on thematerials to increase the efficiency and intensity of the mixing andreacting. Low-frequency, high-intensity acoustic energy is used tocreate a near uniform shear field throughout substantially the entirecontinuous process vessel, which results in rapid fluidization, reactionand/or dispersion of materials. Operation at such high accelerationsputs large mechanical stresses into the components of the processvessel, but, as the process vessel is oscillated at or near theresonance of the resonant system, the operation of the device can bequite efficient. Because of these features, the reliability of theequipment at extreme operating conditions is substantially improved andenables the technology to be scaled. Such systems are applicable to awide variety of reactions and mixing applications.

Low frequency acoustic agitation (LFAA) differs from ultrasonic mixingin that the frequency of acoustic energy is orders of magnitude lower.Most ultrasonic (>20 kHz) energies are fully absorbed by the materialimmediately in front of the ultrasonic transducer. LFAA mixing utilizesacoustic energy, in some implementations nominally at 60 Hz (though atother frequency less than 1 kHz in other implementations), that fullypenetrates substantially the entire contents of a process vessel. Theacoustic energy produced by the LFAA can range from a g-force of a fewg's to hundreds of g's. Unlike impeller agitation, which mixes byinducing bulk flow with eddies generated at the impeller edges, the LFAAmixing occurs on a microscale substantially uniformly throughout themixing volume. Additional interactions with the vessel walls causebeneficial bulk flow. Sound waves radiating from the reactor plates areattenuated, scattered, reflected, or propagated as they transmit througha non-homogeneous media. Attenuation creates an energy gradient whichcorresponds to a body force onto the media being mixed. This forceinduces macro flow in the media referred to as acoustic streaming. Theacoustic streaming, along with the interaction between the media and themixing vessel, results in the micro-mixing of the media. Because theacoustic field forms throughout the process vessel there are low and inmany cases no mixing dead zones and the shear may be near evenlydistributed throughout the process vessel once the materials arefluidized. The scattering and reflected waves also create body forces onsub-elements of the media with volumes of different density. Dependingon the density ratio and material viscosity, these body forces can besignificant or negligible in performing micro mixing. In someimplementation, both the top and the bottom surfaces of each structurewithin a process vessel, impart acoustic energy on the mixture as ittravels through each level of the vessel.

The process of continuous acoustic mixing can be extended tomicroreactors. A primary feature of microreactors is their small size,which can allow for sufficient rates of heat transfer when conductinghighly exothermic reactions. In the case of a continuous acousticmicroreactor, the reaction vessel can include an elongated tube,conduit, channel, or duct for conveying the reactants and for impartingacoustic energy upon them to promote the desired reaction. The elongatedtube can have various cross sections including, for example and withoutlimitation, circular, semi-circular, elliptical, rectangular, orpolygonal. The elongated tube can include an inlet for receiving one ormore reactants, and an outlet for discharging a product. The elongatedtube can be coiled, wrapped, or folded, etc. within the continuousprocess vessel to increase its length beyond the dimensions of thecontinuous process vessel. An acoustic agitator can agitate thecontinuous process vessel at frequencies and accelerations sufficient toovercome adhesion and surface tension effects of reactants with an innersurface of the elongated tube. In some implementations, a transport gascan be introduced into the tube to enhance agitation. The transport gascan be reactive or inert. In some implementations, the continuousprocess vessel can include an interstitial region within the continuousprocess vessel and surrounding the elongated tube. The interstitialregion can receive a cooling fluid or heating fluid and bring it intocontact with an outer surface of the elongated tube so as tocontinuously transfer heat out of or into the elongated tube. In someimplementations, the elongated tube can include a second inlet along itslength for introducing a midstream reactant. The midstream reactant canreact with a product of an initial reaction that occurred upstream inthe elongated tube. The midstream reactant can also or alternativelyfeed a reaction that requires a shorter reaction/residence time than thereaction among the reactants introduced at the first inlet. Additionalmidstream inlets can be provided to allow for further midstreamreactants to be added at different points along the elongated tube.

The continuous acoustic chemical microreactors of the present disclosureare applicable for a broad range of chemical reactions to include, forexample and without limitation, synthesis reactions, decompositionreactions, single displacement reactions, double displacement reactions,precipitation, acid-base neutralization, organic reactions,reduction-oxidation reactions, as well as reactions that produceprecipitating solids and/or utilize solids as reagents.

FIG. 1 shows an example of a continuous processing system 10 a. Thecontinuous processing system 10 a can include an acoustic agitator 11 aand a continuous process vessel 18 a. The process vessel 18 a caninclude inlets 2 a through 2 e (collectively “inlets 2”) configured forintroducing at least one process ingredient, a plurality of plates 22 aconfigured for directing a flow of the process ingredients through theprocess vessel 18 a, and which are capable of transferring acousticenergy generated by the acoustic agitator 11 a into the processingredients, an outlet 26 a for discharging a product of the processingredients subsequent to the process ingredients passing through aportion of the process vessel 18 a while being exposed to the acousticenergy, and a fastener 30 a for removably coupling the process vessel 18a to the acoustic agitator 11 a. The shape of the process vessel 18 acan be configured in a variety of different implementations and caninclude many different components, as will be discussed in greaterdetail below. The different implementations of the process vessel 18 acan support a variety of processes, for example mixing, combining,drying, coating, segregating, and reacting of process ingredients.

FIG. 1 shows an illustrative implementation of a continuous processingsystem 10 a. In FIG. 1, the processing system 10 a includes a processvessel 18 a coupled to an acoustic agitator 11 a. The acoustic agitator11 a can include an electrical cabinet 12 a and a resonance assembly 14a. The acoustic agitator 11 a can be a RAM® Mixer (RAM), such as thoseavailable from Resodyn Acoustic Mixers (Butte, Mont.). The processingsystem 10 a further includes multiple conduits 2 a to deliver thematerials to the processing system and multiple hoppers 8 a to hold thematerials prior to being introduced into the process vessel 18 a. Theconduits 2 a can be any type of pipe, conduit or hose used fordelivering materials, such as a solid, gas or fluid. The hoppers 8 a canhave any type of closed geometric figure with a hollow body to hold ortransfer materials into the process vessel 18 a, for example acontainer, barrel, funnel, or vat. The conduits 2 a and hoppers 8 a canbe coupled to the processing system 10 a by a support frame 9 a. Thesupport frame 9 a can be an open structure to connect and hold thecomponents of the processing system 10 a together. The support frame 9can be coupled to the acoustic agitator 11 a, the process vessel 18 a,and the hoppers 8 a. The support frame 9 a can be made up of multiplesections.

FIG. 1 further shows a cutaway view of one implementation of the processvessel 18 a. The process vessel 18 a can include multiple levels, eachof the levels can include at least one of a plurality of plates 22 a.The plates 22 a can be configured to direct materials through theprocess vessel 18 a. The plates 22 a can be made up of many differentmaterials, for example and without limitation, stainless steel,aluminum, and carbon steel. In some implementations, the plates 22 a canhave a stiffness factor of about 5,000 lbf/in or greater. In otherimplementations, the materials can have other stiffness factor values.The process vessel 18 a can include a heated plate 6 a, a cooling plate6 b, a plurality of inlets 2 a-2 e used for conduits to introducedifferent process ingredients (including, without limitation, mixtureconstituents, coatings, reactants, and/or buffers) at different levelsof the process vessel 18 a, and an exit port 4 to discharge a product ofthe processing system 10 a. The inlets 2 a-2 e can be positioned alongthe top and/or any side of the process vessel 18 a to introducematerials. The exit port 4 can be positioned along a bottom portion ofthe process vessel 18 a.

In some implementations, the process ingredients reacting and mixing inthe process vessel 18 a can form a fluidized bed inside the processvessel 18 a. The processing system 10 a is well suited to createfluidized beds, with material particle sizes that range from nano-sizedparticles to particles the size of tablets. Because the fluidization isformed by vibration, processing system 10 a can fluidize nano-particlesand all sizes up to tablets. The fluidized bed can be created at eachlevel of the process vessel 18 a.

FIG. 2 shows a cutaway perspective view of a continuous process vessel18 j, according to an illustrative implementation. Instead of theprocess vessel 18 j being configured with plates 22 a, as shown in FIG.1, the process vessel 18 j includes coiled pipes 70 for processing thematerials. The process vessel 18 j includes an inlet 20 j, the coiledpipes 70 and an outlet 26 j. Materials can be introduced to the processvessel 18 j through the inlet 20 j and pass through the process vessel18 j through the coiled pipes 70. The coiled pipes can be configured ina helix or spiral formation inside the process vessel 18 j. In someimplementations, the process vessel 18 j can include compact coiledpipes to save space and maximize length of the reaction, and/or mixingprocess. The compact coiled pipes can allow for more coiled pipe lengthin the process vessel 18 j to allow the materials to be in processlonger. Once the materials have been substantially reacted, they can bedischarged through the outlet 26 j.

In some implementations, the process vessel 18 can be a microreactor. Aprimary feature of microreactors is their small size, which can allowfor sufficient rates of heat transfer when conducting highly exothermicreactions. FIG. 3 shows an example process vessel 18 w suitable for useas a continuous acoustic chemical microreactor, according to anillustrative implementation. The process vessel 18 w includes anelongated tube 70 w coupled at a first end to a reactant inlet 20 w andat a second end to a product outlet 26 w. The reactant inlet 20 w canreceive one or more reactants and introduce them in to the elongatedtube 70 w. The outlet 26 w can discharge a product of the reactantsfollowing a reaction among the reactants in the elongated tube 70 w. Insome implementations, the inlet 20 w can be configured to additionallyreceive a transport gas for improving mixing action within the elongatedtube 70 w.

The elongated tube 70 w can be a pipe, tube, conduit, or duct suitablefor conveying liquid, solid, gas, or plasma reactants. The elongatedtube 70 w can be sufficiently robust to handle large alternatingaccelerations induced externally while reactants impact the innersurfaces. The accelerations imparted by the acoustic agitator reach ag-force of 10 g, 20 g, 40 g, 60 g, 80 g, or more. The elongated tube 70w can have dimensions and properties suitable for acting as amicroreactor for highly exothermic reactions. For example, its internalvolume can be kept relatively small and its thermal conductivityrelatively high. In some implementations, the elongated tube 70 w canhave an inner surface having a hydraulic diameter of less than 2.5 cm.In some implementations, the hydraulic diameter can be between 1.5 and2.5 cm. In some implementations, the hydraulic diameter can be between0.5 and 1.5 cm. In some implementations, the elongated tube 70 w canhave an inner surface having a hydraulic diameter of less than 0.5 cm.The elongated tube 70 w can be made of materials that will not react, orreact only little, when in contact with certain reactants or products.For example and without limitation, the elongated tube 70 w can be madeof a glass, metal, ceramic, or polymer. Appropriate metals may includestainless steel, molybdenum, titanium, or monel. Other suitableelongated tubes 70 w can include combinations of materials, such as apolymer- or glass-lined metals. In some implementations, it may bebeneficial for the elongated tube 70 w to have good thermal conductivityfor conducting heat away from exothermic reactions, or heat intoendothermic reactions. For example and without limitation, in someimplementations the elongated tube 70 w can have a thermal conductivitygreater than 10 watts per meter-kelvin, roughly that of some stainlesssteel alloys. In some implementations, the inner surface of theelongated tube 70 w can be coated with a catalyst. Such catalysts caninclude, for example and without limitation, metals, metal oxides,non-metals, ceramics, polymers, and nanoparticles or nanostructures.

To ensure adequate residence time for reactions, the elongated tube 70 wcan be relatively long relative to its width. In some implementations,the elongated tube 70 w is at least 5 cm long. In some implementations,the elongated tube 70 w can be up to 4 m long. In some implementations,the elongated tube 70 w can be between 10 cm and 1 m long. The elongatedtube 70 w can have various shapes. The elongated tube 70 w can take theshape of a helix, spiral, series of spirals, or any other folded orwrapped shape suitable for fitting its entire length within the processvessel 18 s. The elongated tube 70 w can have various cross-sectionalshapes. In some implementations, the elongated tube 70 w can have innerand outer surfaces having a circular, elliptical, or polygonal crosssection. In some implementations, the inner surface of the elongatedtube 70 w can be smooth around its perimeter and/or along its length inthe sense that the inner surface is free of undulations or structuresthat would disrupt laminar flow through when the elongated tube 70 w isstationary. In some implementations, the outer surface of the elongatedtube 70 w can include fins or other protrusions to increase its surfacearea and promote heat conduction.

The process vessel 18 w can be coupled to the acoustic agitator 11,which can agitate the process vessel 18 w along an oscillation axis. Theoscillation axis may be aligned vertically; i.e., parallel with thedirection of gravitational pull. When the process vessel 18 w isagitated, an inner surface of the elongated tube 70 w can impartacoustic energy on the reactants by accelerating the reactants inalternating upward and downward directions along the oscillation axis.The elongated tube 70 w can be aligned normal to the oscillation axissuch that the upper and lower portions of the inside surface agitate thereactants when the elongated tube 70 w is oscillated along theoscillation axis. In some implementations, the elongated tube 70 w canbe positioned such that it is at, or close to, a right angle withrespect to the oscillation axis. In some implementations, the elongatedtube 70 w can be positioned such that it is at an angle of 80 to 90°with respect to the oscillation axis such that it is angled downward inthe direction of desired bulk flow. In some implementations, theelongated tube 70 w can be positioned such that it is at an angle of 65to 80° with respect to the oscillation axis such that it is angleddownward in the direction of desired bulk flow. In some implementations,the elongated tube 70 w can be positioned such that it is at an angle of45 to 65° with respect to the oscillation axis such that it is angleddownward in the direction of desired bulk flow. The acoustic agitator 11can be powerful enough to agitate the process vessel 18 w at high ratesof acceleration. In some implementations, the acoustic agitator isconfigured to agitate the continuous process vessel with an accelerationgreater than 60 g. In some implementations, the acoustic agitator andthe continuous process vessel can operate at a mechanical resonance ofthe acoustic agitator-continuous process vessel system. Operating at amechanical resonance allows for energy efficient operation of theacoustic agitator under highly kinetic conditions. In someimplementations, the acoustic agitator can agitate the continuousprocess vessel at a frequency greater than 10 Hz and less than 100 Hz.

In some implementations, the process vessel 18 w can include featuresfor removing heat from, or adding heat to, the reaction chamber; i.e.,the elongated tube 70 w. For example, the process vessel 18 w caninclude a second inlet 42 w for receiving a fluid, such as a coolingfluid or a heating fluid, a cavity or interstitial region 52 w withinthe process vessel 18 w and surrounding the elongated tube 70 w, and anoutlet 43 w for discharging the fluid from the interstitial region 52 w.Fluid within the interstitial region 52 w can circulate around, and comeinto contact with, an outer surface of the elongated tube 70 w to removeheat from an exothermic reaction occurring within the elongated tube 70w, or provide heat to an endothermic reaction occurring within theelongated tube 70 w. Circulation of the fluid can occur through externalpumping and/or through the agitation of the process vessel 18 w. In someimplementations, the fluid can flow through the interstitial region 52 win substantially the same direction as reactants flowing through theelongated tube 70 w. In some implementations, the fluid can flow throughthe interstitial region 52 w in a direction substantially counter to thedirection of the flow of reactants flowing through the elongated tube 70w.

In some implementations, the process vessel 18 can include a secondinlet for receiving a midstream reagent. The second inlet can introducethe midstream reagent into a midpoint (not necessarily the exactgeometric midpoint) somewhere along the elongated tube. A midstreamreagent can react with a product of an initial reaction occurring in theportion of the elongated tube upstream from the second inlet or themidstream reagent may be added after some reaction has already takenplace because it reacts faster than the other reactants. FIG. 4 shows anexample process vessel 18 x having a second inlet for receiving amidstream reactant, and suitable for use as a continuous acousticchemical microreactor, according to an illustrative implementation. Theprocess vessel 18 x includes an elongated tube 70 x having a firstportion 71 x and a second portion 72 x coupled in series. The propertiesof the elongated tube 70 x can be similar to those of the elongated tube70 w described previously. The elongated tube 70 x is coupled at a firstend to a reactant inlet 20 x and at a second end to a product outlet 26x. The reactant inlet 20 x can receive one or more reactants andintroduce them in to the first end of the elongated tube 70 x. Theoutlet 26 x can discharge a product of the reactants and midstreamreactants following a reaction in the elongated tube 70 x. The processvessel 18 x includes a second inlet 21 x coupled to the elongated tube70 x at a point where the first portion 71 x and the second portion 72 xmeet. The second inlet 21 x can receive one or more midstream reactantsand introduce them into the second portion 71 x. Additional midstreaminlets can be provided to allow for further midstream reactants to beadded at different points along the elongated tube 70 x.

The process vessel 18 x can be coupled to the acoustic agitator 11,which can agitate the process vessel 18 x along an oscillation axis.When the process vessel 18 x is agitated, an inner surface of theelongated tube 70 x can impart acoustic energy on the reactants andmidstream reactants by accelerating the reactants and midstreamreactants in alternating upward and downward directions with respect tothe oscillation axis.

In some implementations, the process vessel 18 x can include featuresfor removing heat from, or adding heat to, the reaction chamber; i.e.,the elongated tube 70 x. For example, the process vessel 18 x caninclude a second inlet 42 x for receiving a fluid, such as a coolingfluid or a heating fluid, a cavity or interstitial region 52 x withinthe process vessel 18 x and surrounding the elongated tube 70 x, and anoutlet 43 x for discharging the cooling fluid from the interstitialregion 52 x. Fluid within the interstitial region 52 x can circulatearound and come into contact with an outer surface of the elongated tube70 x to remove heat from an exothermic reaction occurring within theelongated tube 70 x, or provide heat to an endothermic reactionoccurring within the elongated tube 70 x. Circulation of the fluid canoccur through external pumping and/or through the agitation of theprocess vessel 18 x. In some implementations, the fluid can flow throughthe interstitial region 52 x in substantially the same direction asreactants flowing through the elongated tube 70 x. In someimplementations, the fluid can flow through the interstitial region 52 xin a direction substantially counter to the direction of the flow ofreactants flowing through the elongated tube 70 x. FIGS. 5A and 5B,described below show example experimental setups of continuous acousticchemical microreactors, according to an illustrative implementation.

FIG. 5A shows an example experimental setup of a continuous acousticchemical microreactor 500, according to an illustrative implementation.The microreactor 500 includes a first inlet 510 for receiving a firstliquid (Liquid 1), a second inlet 510 for receiving a second liquid(Liquid 2), and a gas inlet 530 for receiving a transport gas or gasreactant. In some implementations, the first inlet 510 and second inlet520 can receive additional liquid or solid reagents or reactants. Anelongated tube 540 coupled to the inlets receives the reactants and gasand serves as a reaction chamber. An outlet 550 coupled to the elongatedtube 540 receives a product of the reaction from the elongated tube 540and discharges it from the microreactor 500 so it can be analyzed. Themicroreactor 500 is mounted on an acoustic agitator such as the acousticagitator 11 a previously described.

The microreactor 500 was used for a series of tests to qualitativelygauge its performance under different amplitudes of agitation. For thisseries of tests, the liquid flow was ˜150 ml/min and the gas volumefraction was ˜30%. Acceleration of the microreactor 500 was varied from0 to 100 g in 20 g increments. It was observed that the mixing processwithin the elongated tube 540 varied as a function of the accelerationapplied. It was deemed appropriate to classify the mixingcharacteristics into two general regimes: (1) a compressive gas mixregime and (2) a highly chaotic splitting and combining regime. Theregime change varies in accordance with acceleration. At accelerationsbelow ˜40 g bubbles maintain some structure and pulse as they move alongthe elongated tube 540, with very small pulsations at 0 g and increasingup to ˜40 g.

Above ˜40 g, a transition occurs, and the bubble structure breaks down.Sheets and droplets of liquid become more dispersed into the continuousphase of gas within the tube. The gas-liquid interfacial area increasesand the mixing becomes chaotic in form. The chaotic features of the mixincrease as the acceleration is increased above 40 g, become fullyformed at ˜60 g, and increase in intensity up to ˜80 g, where it is hardto discern addition chaotic mixing features from ˜80 g to the maximumtested operating condition of 100 g (higher levels of acceleration maybe employed for other use cases without departing from scope of thisdisclosure).

Throughout the chaotic mixing regime the fluid appears to be propelledacross the diameter of the elongated tube 540 from one portion of theinner surface to the other, corresponding to the agitating motion of theelongated tube 540 as it is vibrated by the acoustic agitator. Themixing regime showed a lack of bubbly structure and more of a froth-likemixing regime over 60 g as noted above.

A certain proportion of gas within the microreactor 540—i.e., thegas-volume fraction—can promote high levels of mixing. The gas can be ofany type desired, ranging from reactive to inert. Suitable gases caninclude, without limitation, air, nitrogen, oxygen, argon, hydrogen,helium, carbon dioxide, neon, fluorine, chlorine, xenon, or othervapors, or combinations thereof.

FIG. 5B shows an example experimental setup of a continuous acousticchemical microreactor 501, according to an illustrative implementation.The microreactor 501 includes a first inlet 560 for receiving a firstliquid, in this case water, and a gas inlet 570 for receiving atransport gas or gas reactant, in this case nitrogen. An elongated tube580 coupled to the inlets receives the water and nitrogen and serves asa reaction chamber. An outlet 590 coupled to the elongated tube 580receives a product of the reaction from the elongated tube 580 anddischarges it from the microreactor so it can be analyzed. The entireapparatus is mounted on an acoustic agitator such as the acousticagitator 11 a previously described.

The microreactor 501 was used for a series of tests to measuregas-liquid mass transport in a small diameter tube as a means toestablish the feasibility of using acoustic agitator 11 to enhancemicroreactor productivity. Water was fed into the elongated tube 580 viathe first inlet 560, as nitrogen was fed into the elongated tube 580 viathe gas inlet 570. The acoustic agitator agitated the elongated tube 580along the oscillation axis shown in the diagram, and the dissolvedoxygen was measured in the product discharged from the outlet 590. Thedissolved oxygen readings were taken every 5 seconds. The rate ofnitrogen replacement of the dissolved oxygen in the water was used inEquation 1 below to determine the volumetric mass transfer coefficient(k_(L)a) at acceleration (g) levels of 0, 40 60, 80 and 100 g. (Picturesin FIG. 4, above, illustrated the relative gas-liquid mixing conditionsat each of these accelerations.)

$\begin{matrix}{{k_{L}a} = {\frac{1}{t}\ln \frac{c_{in} - c_{equ}}{c_{out} - c_{equ}}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

FIG. 6A shows example results 600 of experiments conducted with thecontinuous acoustic chemical microreactor shown in FIG. 5B at differentinlet gas flows and accelerations. The data depicted in FIG. 6A showsk_(L)a as a function of vertical tube acceleration for accelerationlevels of 0, 40, 60, 80 and 100 g, at nitrogen gas fractions of 5, 10,25, and 50%. The results 600 show measured k_(L)a values exceeding eventhe highest Continuous Stirred Tank Reactor (CSTR) k_(L)a values foundin the literature.

FIG. 6B shows example results 601 of experiments conducted with thecontinuous acoustic chemical microreactor shown in FIG. 5B versus aCorning Advances-Flow™ Reactor at different inlet gas flows andaccelerations. FIG. 6B shows a comparison of the microreactor 501 (RAM)k_(L)a values for the 10% gas and 33% gas conditions in comparison toresults published by Corning for their microreactor, called theAdvanced-Flow™ Reactor (AFR) at comparable gas flow rates. In bothsituations the microreactor 501 k_(L)a values exceed the reported AFRvalues at acceleration levels of ˜60 g and greater. As shown in Table 1below, the gas-liquid mass transport coefficient for the microreactor501 was substantially better than that for the Corning AFR despitehaving a shorter residence time in the reaction zone.

TABLE 1 Gas-liquid mass transport results from the experimentalmicroreactor 501 compared to published Corning Advanced- Flow ™ Reactordata Corning CAR Corning CAR AFR (100 g) AFR (100 g) % Gas 15% 10% 30%33% Residence Time (s) 6.5 0.8 6.5 0.8 Liquid Flow Rate (ml/min) 80 10080 100 k_(L)a (1/s) 0.4 0.9 1.4 1.7

The microreactor 501 kLa need not depend upon turbulence developed byflow through the tubes. The microreactor 501 mixing can depend solely orprimarily upon the acceleration and is therefore independent of theReynolds number. This finding means that the microreactor 501 can have awide flow turn-up and turn-down window and not require turbulent flowthrough the microreactor channels.

FIG. 7A shows example results 600 of experiments conducted with acontinuous acoustic chemical microreactor measuring mixing time versusacceleration. The experiment is based on the iodide/iodate chemical testreaction, also called the Villermaux-Dushman method, which uses parallelcompeting reactions having different speeds. Briefly, good mixing favorsthe faster reaction, and the presence of an undesirable byproduct can bemeasured to quantify the effectiveness of mixing. The experiment wasconducted to compare the effectiveness of a continuous acoustic chemicalmicroreactor of the present disclosure with the Corning AFR™ unitpreviously described.

The results 600 of the Villermaux-Dushman method test are shown in FIG.7A. The results 600 show that, at 80 g, the continuous acoustic chemicalmicroreactor can achieve a mixing time of 5 ms, as compared to 10-20 msas listed in the data published for the Corning AFR™ for the samereaction.

FIG. 7B shows example results 601 of experiments conducted with acontinuous acoustic chemical microreactor measuring mix quality versusacceleration. The results 601 show that at 80 g, the continuous acousticchemical microreactor can achieve a mix quality of 94%, as compared to90% as listed in the data published for the Corning AFR™ for the samereaction. The results 600 and 601 show that the continuous acousticchemical microreactor can outperform the Corning AFR™ in both mixingtime and quality at and above 60 g of acceleration.

An example method of operation of the continuous processing system 10 awill now be described with reference to FIG. 8.

FIG. 8 is a flowchart of an example method 800 method of continuouslyprocessing a combination of materials in a chemical microreactor,according to an illustrative implementation. The method 800 can beperformed using a continuous acoustic mixer such as the continuousprocessing system 10 including, for example, one of the process vessels18 j, 18 w, or 18 x previously described. The method 800 includesintroducing, via a reactant inlet, one or more reactants into anelongated tube coupled at a first end to the reactant inlet andconfigured to receive the reactants from the reactant inlet (stage 810).The method 800 includes agitating, using an acoustic agitator coupled tothe continuous process vessel, the continuous process vessel along theoscillation axis such that the inner surface of the elongated tubeaccelerates the one or more reactants in alternating upward and downwarddirections with respect to the oscillation axis (stage 820). The method800 includes discharging, from a product outlet coupled to a second endof the elongated tube, a product of a chemical reaction from thecontinuous process vessel (stage 830).

The method 800 includes introducing, via a reactant inlet, one or morereactants into an elongated tube coupled at a first end to the reactantinlet and configured to receive the reactants from the reactant inlet(stage 810). To ensure adequate heat removal for highly exothermicreactions, the elongated tube, such as elongated tube 70, 70 w, or 70 x,can be thermally conductive and have a relatively small cross-sectionalarea such that the surface area-to-volume ratio remains relatively highto promote rapid conduction of heat away from the elongated tube. Forexample, the elongated tube can have an inner surface having a hydraulicdiameter of less than 2.5 cm. In some implementations, the method 800can include introducing a transport gas into the reactant inletsimultaneously or sequentially with the reactants. The transport gas canaid mixing by allowing liquid reactants to froth and mix more vigorouslyand achieve a chaotic, frothy state. The transport gas can be reactiveor inert. In some implementations, a certain gas-volume fraction can bemaintained for increased rates of mixing. For example, transport gas canbe introduced to maintain a gas-volume fraction of at least 30%.

The method 800 includes agitating, using an acoustic agitator coupled tothe continuous process vessel, the continuous process vessel along theoscillation axis such that the inner surface of the elongated tubeaccelerates the one or more reactants in alternating upward and downwarddirections with respect to the oscillation axis (stage 820). In someimplementations, the acoustic agitator can agitate the continuousprocess vessel at high rates of acceleration. For example, in someimplementations, the acoustic agitator can agitate the continuousprocess vessel at an acceleration greater than 60 g and up to 200 g.Accelerations greater than 60 g can cause breakdown of the bubblestructure of liquid reactants and transport gas and increase thegas-liquid interfacial area. Throughout the chaotic mixing regime, thereactants will be propelled across the cross section of the elongatedtube from one wall to the other, corresponding to the agitating motionof the process vessel as it is vibrated by the acoustic agitator. Insome implementations, the acoustic agitator and the continuous processvessel can operate at a mechanical resonance. Operating at a mechanicalresonance allows for energy efficient operation of the acoustic agitatorunder highly kinetic conditions. In some implementations, the acousticagitator can agitate the continuous process vessel at a frequencygreater than 1 Hz and less than 1 KHz. In some implementations, theacoustic agitator can agitate the continuous process vessel at afrequency greater than 10 Hz and less than 100 Hz.

In some implementations, the method 800 can include introducing amidstream reactant into the elongated tube via a second reactant inletcoupled to the elongated tube. The midstream reactants can be, forexample and without limitation, reactants requiring less residence timewithin the process vessel, or reactants intended to react with a productof an initial reaction occurring in the upstream portion of theelongated tube.

The method 800 includes discharging, from a product outlet coupled to asecond end of the elongated tube, a product of a chemical reaction fromthe continuous process vessel (stage 830).

In some implementations, the method 800 can include introducing, via acoolant inlet, a cooling fluid into an interstitial region within thecontinuous process vessel and surrounding the elongated tube. Thecooling fluid can circulate around and conduct heat away from an outersurface of the elongated tube. The method 800 can include discharging,via a coolant outlet, the cooling fluid from the interstitial region soas to remove heat from exothermic reactions occurring within theelongated tube.

In some implementations, the method 800 can include introducing, via aheater inlet, a heating fluid into an interstitial region within thecontinuous process vessel and surrounding the elongated tube, or duct.The heating fluid can circulate around and conduct heat into an outersurface of the elongated tube. The method 800 can include discharging,via a heater outlet, the heating fluid from the interstitial region. Theheating fluid can add heat to initiate chemical reactions, oraccommodate endothermic reactions occurring within the elongated tube.

FIGS. 9A through 9D illustrate different views of an example horizontalplate process vessel 918 suitable for use as a continuous acousticchemical microreactor, according to an illustrative implementation. Theprocess vessel 918 includes a plate 910 defining an elongated tube,referred to with respect to this implementation as a reaction channel970. FIG. 9A illustrates a first horizontal cross section of the plate910 showing the various channels defined therein including the reactionchannel 970. FIG. 9B illustrates a second horizontal cross section ofthe plate 910 showing various inputs and outputs defined therein. Thefirst and second horizontal cross sections of FIGS. 9A and 9B,respectively, are taken at different points along an axis perpendicularto the cross section; for example, the first cross section may be takenat a point above or below the second cross section along the axis. FIG.9C illustrates a vertical cross section of the process vessel 918showing the plate 910 and other components. As shown in FIG. 9C, theoscillation axis of the process vessel 918 lies in the vertical plane;that is, the oscillation axis is perpendicular to the horizontal planesof the cross sections illustrated in FIGS. 9A and 9B. FIG. 9Dillustrates a perspective view of the process vessel 918.

FIG. 9A illustrates the first horizontal cross section of the plate 910of the process vessel 918, according to an illustrative implementation.The plate 910 defines several channels including the reaction channel970, which conveys reactants, reagents, transit gasses, reactionproducts, et cetera through the process vessel 918, and channels 952 athrough 952 f (collectively “channels 952”), which can convey heating orcooling fluids through the plate 910 to add or remove heat fromreactions occurring within the reaction channel 970. In someimplementations, the plate 910 can define more or fewer channels. Theplate 910 additionally defines several orifices including inlet orifices925 a and 925 b (collectively “inlet orifices”), an outlet orifice 927,inlet orifices 945 a through 945 f (collectively “inlet orifices 945”),outlet orifices 946 a through 946 f (collectively “outlet orifices946”), and inlet orifices 922 a and 922 b (collectively “inlet orifices922”). Each of the various orifices connects its respective channel toone of the various inlets or outlets defined in the plate 910 anddescribed below with reference to FIG. 9B. The various orifices cantherefore pass substances between the various channels and the variousinlets and outlets.

The reaction channel 970 can receive reactants, reagents, transit gas,et cetera from the inlet orifices 925. These substances can be actedupon by an inner surface of the reaction channel 970 as the processvessel 918 is agitated by an acoustic agitator, such as the acousticagitator 11 a previously described. The agitation can promote mixing orreaction of the substances within the reaction channel 970. In additionto the agitation, which occurs substantially along the axisperpendicular to the cross section, the substances exhibit a bulk flowthrough the reaction channel 970 from the inlet orifices 925 to theoutlet orifice 927, which passes the substances to an outlet 926 shownin FIG. 9B. In some implementations, the plate 910 can define one ormore inlet orifices 922 for receiving midstream reactants, similar tothe process vessel 18 x described above with reference to FIG. 4.

The channels 952 can receive heating or cooling fluids via the inletorifices 945, and pass them out of the outlet orifices 946. In someimplementations, the inlet orifices and outlet orifices can be reversed;that is, the heating/cooling fluids can travel through the channels 952in the same direction as the reactants in the reaction channel 970. Insome implementations, certain channels 952 can pass a heating fluidwhile other channels pass a cooling fluid. For example, the channels 952a and 952 b may receive a heating fluid via the inlet orifices 945 a and945 b, while the channels 952 e and 952 f receive a cooling fluid viathe inlet orifices 945 e and 945 f, or vice-versa. The inlet orifices945 connect to inlets 942 shown in FIG. 9B, and the outlet orifices 946connect to outlets 943 also shown in FIG. 9B.

FIG. 9B illustrates the second horizontal cross section of the plate 910of the process vessel 918, according to an illustrative implementation.As shown in FIG. 9B, the plate 910 defines various inlets and outletsfor receiving and passing different substances including reactants,reagents, transit gasses, products, and heating/cooling fluids. Thevarious inlets and outlets connect to the various inlet orifices andoutlet orifices shown in FIG. 9A. In particular, the inlet 920 aconnects to the reaction channel 970 via the inlet orifice 925 a, andthe inlet 920 b connects to the reaction channel 970 via the inletorifice 925 b. Similarly, the inlets 921 a and 921 b connect to thereaction channel 970 via the inlet orifices 922 a and 922 b,respectively. The reaction channel 970 connects to the outlet 926 viathe outlet orifice 927. The inlet 942 a for heating/cooling fluidsconnects to the channels 952 a and 952 b via the inlet orifices 945 aand 945 b, respectively, and the channels 952 a and 952 b connect to theoutlet 943 a via the outlet orifices 946 a and 946 b, respectively. Theinlet 942 b for heating/cooling fluids connects to the channels 952 cand 952 d via the inlet orifices 945 c and 945 d, respectively, and thechannels 952 c and 952 d connect to the outlet 943 b via the outletorifices 946 c and 946 d, respectively. The inlet 942 c forheating/cooling fluids connects to the channels 952 e and 952 f via theinlet orifices 945 e and 945 f, respectively, and the channels 952 e and952 f connect to the outlet 943 c via the outlet orifices 946 a and 946b, respectively. In some implementations, the plate 910 can define moreor fewer channels and corresponding inlets, outlets, and orifices. Theinlets and outlets can be configured to receive and pass substances viahoses or pipes connected thereto. Accordingly, the inlets and outletsmay include features for receiving and retaining the hoses or pipes suchas threads, flanges, or edges.

FIG. 9C shows a vertical cross sections of an example horizontal plateprocess vessel 918 suitable for use as a continuous acoustic chemicalmicroreactor, according to an illustrative implementation. The processvessel 918 can include an upper cap 930, a seal 940, a cap plate 950, aseal 960, the plate 910 previously described, a seal 980, a base plate990, and a mounting flange 995. The process vessel 918 assembly can beheld together by bolts 905, and mount to the acoustic agitator via themounting plate 995. In some implementations, the process vessel 918 canbe removably mounted to the acoustic agitator using bolts, clips,clamps, clasps, or other fasteners. The cap plate 950 can defineadditional channels 955, which can be used for conveying additionalheating or cooling fluids in proximity to the reaction channel 970. Theheating or cooling fluid can be held within the cavity formed by theupper cap 930. The cavity formed by the upper cap 930 can be similar tothe interstitial regions 52 w and 52 x previously described. The capplate 950 and plate 910 can be made of a thermally conductive materialsuch as a metal or alloy to promote heat transfer between the reactionchannel 970 and the channels 952 and 955. The process vessel 918 can beconfigured to oscillate along the oscillation axis shown in FIG. 9C.

FIG. 9D shows a perspective view of an example horizontal plate processvessel 918 suitable for use as a continuous acoustic chemicalmicroreactor, according to an illustrative implementation.

Many variations of the present application will occur to those skilledin the art. Some variations may include elongated tubes of differentshapes and sizes. Some variations may include additional inlets forreceiving additional reactants or non-reactive materials at differentpoints along the elongated tube. Other variations may have mixingregions having different dimensions or shapes. All such variations areintended to be within the scope and spirit of the present application.

Although some implementations are shown to include certain features orsteps, the applicants specifically contemplate that any feature or stepdisclosed herein can be used together or in combination with any otherfeature or step on any implementation of the present application. It isalso contemplated that any feature or step can be specifically excludedfrom any implementation of the present application.

While the disclosure has been disclosed in connection with theimplementations shown and described in detail, various modifications andimprovements thereon will become readily apparent to those skilled inthe art. Accordingly, the spirit and scope of the present disclosure isto be limited only by the following claims.

What is claimed is:
 1. A continuous acoustic chemical microreactorsystem comprising: a continuous process vessel configured to oscillatealong an oscillation axis, the continuous process vessel including: areactant inlet configured to receive one or more reactants into thecontinuous process vessel; an elongated tube coupled at a first end tothe reactant inlet and configured to receive the reactants from thereactant inlet, wherein the elongated tube has an inner surface having ahydraulic diameter of less than 2.5 cm; and a product outlet coupled toa second end of the elongated tube and configured to discharge a productof a chemical reaction among the reactants from the continuous processvessel; and an acoustic agitator coupled to the continuous processvessel and configured to agitate the continuous process vessel along theoscillation axis such that the inner surface of the elongated tubeaccelerates the one or more reactants in alternating upward and downwarddirections along the oscillation axis.
 2. The system of claim 1, whereinthe acoustic agitator is configured to agitate the continuous processvessel with an acceleration greater than 60 g.
 3. The system of claim 1,wherein the elongated tube is at least 10 cm long.
 4. The system ofclaim 1, wherein the elongated tube has an inner surface having ahydraulic diameter of less than 0.5 cm.
 5. The system of claim 1,wherein the continuous process vessel includes: a coolant inletconfigured to receive a cooling fluid; an interstitial region within thecontinuous process vessel and surrounding the elongated tube, theinterstitial region configured to receive the cooling fluid and bring itinto contact with an outer surface of the elongated tube; and a coolantoutlet for discharging the cooling fluid from the interstitial region.6. The system of claim 1, wherein the continuous process vesselincludes: a heater inlet configured to receive a heating fluid; aninterstitial region within the continuous process vessel and surroundingthe elongated tube, the interstitial region configured to receive theheating fluid and bring it into contact with an outer surface of theelongated tube; and a heater outlet for discharging the heating fluidfrom the interstitial region.
 7. The system of claim 1, wherein theinlet is configured to receive a transport gas.
 8. The system of claim1, wherein the system is configured to operate at mechanical resonance.9. The system of claim 1, comprising: a second reactant inlet coupled tothe elongated tube at a point between the first end and the second endand configured to receive a midstream reactant and introduce it into theelongated tube.
 10. The system of claim 1, wherein the inner surface ofthe elongated tube has a cross section that is substantially circular.11. The system of claim 1, wherein the inner surface of the elongatedtube has a cross section that is substantially ovular.
 12. The system ofclaim 1, wherein the inner surface of the elongated tube has a crosssection that is substantially rectangular.
 13. The system of claim 1,wherein the inner surface of the elongated tube has a cross section thatis substantially square.
 14. The system of claim 1, wherein the innersurface of the elongated tube has a cross section that is substantiallytriangular.
 15. The system of claim 1, wherein the inner surface of theelongated tube is smooth.
 16. The system of claim 1, wherein the innersurface of the elongated tube is rough.
 17. The system of claim 1,wherein the inner surface of the elongated tube is coated with acatalyst.
 18. The system of claim 1, wherein the acoustic agitator isconfigured to agitate the continuous process vessel at a frequencygreater than 10 Hz and less than 100 Hz.
 19. A method of continuouslyprocessing a combination of materials in a chemical microreactor, themethod comprising: introducing, via a reactant inlet, one or morereactants into an elongated tube coupled at a first end to the reactantinlet and configured to receive the reactants from the reactant inlet,wherein the elongated tube has an inner surface having a hydraulicdiameter of less than 2.5 cm; agitating, using an acoustic agitatorcoupled to the continuous process vessel, the continuous process vesselalong the oscillation axis such that the inner surface of the elongatedtube accelerates the one or more reactants in alternating upward anddownward directions along the oscillation axis; and discharging, from aproduct outlet coupled to a second end of the elongated tube, a productof a chemical reaction among the reactants from the continuous processvessel.
 20. The method of claim 19, comprising: introducing, via acoolant inlet, a cooling fluid into an interstitial region within thecontinuous process vessel and surrounding the elongated tube, theinterstitial region configured to receive the cooling fluid and bring itinto contact with an outer surface of the elongated tube; anddischarging, via a coolant outlet, the cooling fluid from theinterstitial region.
 21. The method of claim 19, comprising:introducing, via a heater inlet, a heating fluid into an interstitialregion within the continuous process vessel and surrounding theelongated tube, the interstitial region configured to receive theheating fluid and bring it into contact with an outer surface of theelongated tube; and discharging, via a heater outlet, the heating fluidfrom the interstitial region.
 22. The method of claim 19, comprising:introducing a midstream reactant into the elongated tube via a secondreactant inlet coupled to the elongated tube at a point between thefirst end and the second end.
 23. The method of claim 19, comprising:introducing a transport gas into the reactant inlet.
 24. The method ofclaim 23, wherein the transport gas is introduced to maintain a gasfraction in the elongated tube greater than 5% and less than 90%. 25.The method of claim 19, comprising: agitating the continuous processvessel with an acceleration greater than 60 g.
 26. The method of claim19, comprising: agitating the continuous process vessel at a frequencygreater than 10 Hz and less than 100 Hz.
 27. The method of claim 19,comprising: agitating the continuous process vessel at a mechanicalresonance of the combined acoustic agitator and continuous processvessel system.